This view is wrong, isn't it?

There are several possibilities for thinness: first, no exercise and underdeveloped muscles; Second, the absorption is not good, consumption is not as good as intake, and of course you can't be fat.

Some simple and effective ways to strengthen yourself by exercising muscles, such as using dumbbells, push-ups, pull-ups to exercise chest, shoulders and arms muscles, and using leapfrog, running and heel lifting to exercise legs.

In a word, exercise is good.

But please pay attention to the method, safety first!